This invention relates to tube winding machines, and more particularly to improved methods and apparatus for tensioning and applying glue to the strips of paper or other materials being wound.
Tube making apparatus in which several strips or tapes of paper or other similar materials are wound around a mandrel in overlapping helixes to form a continuous tube are well known as shown, for example, by Meyer U.S. Pat. No. 4,473,368. Glue is typically applied to at least some of the strips prior to winding in order to hold the tapes together in the finished tube. The quality and uniformity of the finished tube depends to a significant degree on the amount and uniformity of the tension applied to the strips going to the mandrel. Different amounts of tension may be required for different strips for such reasons as the position of the strip in the finished tube (i.e., whether the strip is the inner strip, the outer strip, or an intermediate strip in the finished tube) and the tensile strength of the strip. It is also desirable to be able to individually adjust the amount of glue applied to each strip, to completely remove all strips from contact with the glue source when the machine is stopped, and to ensure that the tapes cannot become entangled in the glue applying mechanism in the event that a tape breaks or under any other machine operating condition.
In view of the foregoing, it is an object of this invention to improve the mechanisms used for tensioning and applying glue to the tapes going to the mandrel of a spiral tube winding machine.
It is a more particular object of this invention to provide tensioning and glue applying mechanisms of the type mentioned above in which the amount of tension applied to each tape can be easily and individually adjusted.
It is another more particular object of this invention to provide tensioning and glue applying mechanisms of the type mentioned above in which the amount of glue applied to each tape can be easily and individually controlled.
It is still another more particular object of this invention to provide tensioning and glue applying mechanisms of the type mentioned above in which the tapes are automatically removed from contact with the glue applying component whenever the tube winding machine stops.
It is yet another more particular object of this invention to provide tensioning and glue applying mechanisms of the type mentioned above in which the tapes are positively controlled both before and after the point at which the glue is applied to prevent the tapes from becoming entangled in the glue applying components in the event that a tape breaks or under any other machine operating condition.